package icom.acm.util;

import java.util.Random;

public class RandUtil {
	private static Random rand = new Random();	
	
	public static String rndString(int len){
		StringBuffer sb = new StringBuffer();
		for (int i=0;i<len;i++){
			int n = rand.nextInt(26);			
			if (rand.nextBoolean()) n += 65;
			else n+=97;			
			char c = (char)n;
			
			sb.append(c);
		}
		return new String(sb);
	}
	
	public static void main(String[] args){
		System.out.print(rndString(4));
	}
}
